Pietersen is believed to be currently discussing his future with the England hierachy after being dropped this summer for allegedly sending derogatory texts to South African players about Andrew Strauss.
Flintoff has claimed that the team will need Pietersen this winter in Asia, a continent where they usually struggle.
The 34-year-old told The Sun: "I don't know what's happened, nobody does.
"But what we do know is that when he is playing, England are a better side and for that reason, everyone would like to see him back.
"I get on fine with Kevin. He's an individual and he's an individual when he bats. When he's scoring hundreds you just sit and watch and think 'how does he do that?'"
The series with India will be Alastair Cook's first as the captain of the Test team.